Stroll anywhere in the small streets of Bayone and you'll find, between 1 to 3pm, lots of cafés and bars open for lunch, with many offering plats du jour, plate of the day. They serve good food, and since you are technically in Basque territory, you must eat some jambon du Bayone.
After eating, you are welcome to stroll the streets of the old town and buy some handicrafts from street vendors or some sweets at the Hipermarche supermarket to save some dough.
Bayone is about 30 minutes into France from Spain, so it’s a good day trip along with Biarritz for the surfers that read this, as long as you have a place to stash your boards.